U.S. patent number 11,426,223 [Application Number 16/282,388] was granted by the patent office on 2022-08-30 for bone screw and method of manufacture.
This patent grant is currently assigned to Warsaw Orthopedic, Inc.. The grantee listed for this patent is Warsaw Orthopedic, Inc.. Invention is credited to Rodney Ray Ballard, William Alan Rezach.
United States Patent |
11,426,223 |
Ballard , et al. |
August 30, 2022 |
Bone screw and method of manufacture
Abstract
An implant receiver comprises a body formed by a first
manufacturing method, the body including an outer surface and
having spaced apart walls defining a cavity configured for disposal
of a spinal implant; and at least one layer being formed onto at
least a portion of the outer surface by a second manufacturing
method. In some embodiments, systems, spinal constructs, surgical
instruments and methods are disclosed. In some embodiments,
systems, spinal constructs, surgical instruments and methods are
disclosed.
Inventors: |
Ballard; Rodney Ray (Lakeland,
TN), Rezach; William Alan (Covington, TN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Warsaw Orthopedic, Inc. |
Warsaw |
IN |
US |
|
|
Assignee: |
Warsaw Orthopedic, Inc.
(Warsaw, IN)
|
Family
ID: |
1000006528857 |
Appl.
No.: |
16/282,388 |
Filed: |
February 22, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200268425 A1 |
Aug 27, 2020 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F
2/28 (20130101); A61B 17/866 (20130101); A61F
2/30771 (20130101); A61F 2/4611 (20130101); A61F
2/44 (20130101); A61F 2310/00023 (20130101); A61B
17/8605 (20130101); A61L 2430/02 (20130101); A61F
2002/2835 (20130101); A61L 27/3608 (20130101) |
Current International
Class: |
A61B
17/86 (20060101); A61F 2/28 (20060101); A61F
2/44 (20060101); A61F 2/30 (20060101); A61F
2/46 (20060101); A61L 27/36 (20060101) |
Field of
Search: |
;606/246-279 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Ku; Si Ming
Attorney, Agent or Firm: Sorell, Lenna & Schmidt,
LLP
Claims
What is claimed is:
1. An implant receiver comprising: a body formed by a first
manufacturing method, the body extending along a longitudinal axis
between opposite proximal and distal end surfaces, the distal end
surface extending perpendicular to the longitudinal axis, the body
including an outer surface and having spaced-apart walls defining a
cavity configured for disposal of a spinal implant, the walls
extending parallel to the longitudinal axis, the body defining
passageway extending through the distal end surface and parallel to
the longitudinal axis; and at least one layer being formed onto at
least a portion of the outer surface of the body by a second
manufacturing method such that the at least one layer defines a
portion of the passageway, the at least one layer comprising first
and second sections each having a height along the longitudinal
axis, the height of the second section being different than the
height of the first section, the portion of the outer surface
including the distal end surface, the portion of the outer surface
being spaced apart from the walls.
2. The implant receiver recited in claim 1, wherein the body has a
solid configuration relative to the at least one layer.
3. The implant receiver recited in claim 1, wherein the at least
one layer has a porous configuration to promote bone growth through
the at least one layer.
4. The implant receiver recited in claim 1, wherein the at least
one layer includes a roughened surface to promote bone growth
between the implant receiver and bone.
5. The implant receiver recited in claim 1, wherein the body
includes a first portion defining the cavity and a second portion
including a base, the at least one layer being disposed about at
least a portion of an outer circumference of the second
portion.
6. The implant receiver recited in claim 1, wherein the at least
one layer is disposed about an entire outer circumference of the
body.
7. The implant receiver recited in claim 1, wherein the at least
one layer is fabricated by additive manufacturing as the second
manufacturing method.
8. The implant receiver recited in claim 1, wherein the at least
one layer includes a lattice configured to promote bone growth
through the at least one layer.
9. The implant receiver recited in claim 1, wherein the at least
one layer includes a trabecular configuration.
10. The implant receiver recited in claim 1, wherein the at least a
portion of the outer surface of the body provides a fabrication
platform for the at least one layer.
11. The implant receiver recited in claim 1, wherein the cavity
includes a U-shaped cavity configured for disposal of a spinal rod
and the at least a portion of the outer surface includes or is part
of a base of the body.
12. A method for fabricating the implant receiver recited in claim
1, the method comprising the steps of: forming the body by the
first manufacturing method; and forming the at least one layer onto
the portion of the outer surface by the second manufacturing
method, wherein a processor instructs an additive manufacturing
apparatus to form the at least one layer.
13. A method as recited in claim 12, wherein the additive
manufacturing method includes heating a material in a selective
material formation onto the portion of the outer surface.
14. A method as recited in claim 12, wherein the first
manufacturing method includes cutting, grinding, rolling, forging,
molding, casting, extruding and/or cold working.
15. A method as recited in claim 12, wherein the at least one layer
includes a porous layer to promote bone growth through the
layer.
16. A method as recited in claim 12, wherein the at least one layer
includes a roughened surface to promote bone growth with the
body.
17. A method as recited in claim 12, wherein the at least one layer
includes a lattice configured to promote bone growth through the at
least one layer.
18. A method as recited in claim 12, wherein the at least one layer
is disposed about an entire outer circumference of the body.
19. A bone screw comprising: a shaft including at least one thread
having an external thread form; an implant receiver formed by a
first manufacturing method, the implant receiver including spaced
apart walls defining a U-shaped cavity configured for disposal of a
spinal implant and an outer surface, the implant receiver extending
along a longitudinal axis between opposite proximal and distal end
surfaces, the distal end surface extending perpendicular to the
longitudinal axis, the walls extending parallel to the longitudinal
axis, the receiver defining passageway extending through the distal
end surface and parallel to the longitudinal axis; and a layer
formed onto at least a portion of the outer surface by a second
manufacturing method such that the layer defines a portion of the
passageway, the layer comprising first and second sections each
having a height along the longitudinal axis, the height of the
second section being less than the height of the first section, the
second section being positioned between the walls, the layer
comprising a tapered section that connects the first section and
the second section, the portion of the outer surface including the
distal end surface, the portion of the outer surface being spaced
apart from the walls.
20. The bone screw recited in claim 19, wherein the layer is
disposed about an entire outer circumference of the implant
receiver.
Description
TECHNICAL FIELD
The present disclosure generally relates to medical devices for the
treatment of spinal disorders, and more particularly to a spinal
implant system having a variable structured spinal implant that can
be manufactured by a method including one or a plurality of
manufacturing techniques.
BACKGROUND
Spinal pathologies and disorders such as kyphosis, scoliosis and
other curvature abnormalities, degenerative disc disease, disc
herniation, osteoporosis, spondylolisthesis, stenosis, tumor, and
fracture may result from factors including trauma, disease and
degenerative conditions caused by injury and aging. Spinal
disorders typically result in symptoms including deformity, pain,
nerve damage, and partial or complete loss of mobility.
Non-surgical treatments, such as medication, rehabilitation and
exercise can be effective, however, may fail to relieve the
symptoms associated with these disorders. Surgical treatment of
these spinal disorders includes correction, fusion, fixation,
discectomy, laminectomy and implantable prosthetics. As part of
these surgical treatments, spinal constructs including bone
fasteners are often used to provide stability to a treated region.
Such bone fasteners are traditionally manufactured using a medical
machining technique. This disclosure describes an improvement over
these prior technologies.
SUMMARY
In one embodiment, an implant receiver is provided. The implant
receiver comprises a body formed by a first manufacturing method.
The body includes an outer surface and has spaced apart walls that
define a cavity configured for disposal of a spinal implant. At
least one layer is formed onto at least a portion of the outer
surface by a second manufacturing method. In some embodiments,
systems, spinal constructs, surgical instruments and methods are
disclosed.
In one embodiment, a method for fabricating an implant receiver is
provided. The method comprises the steps of: forming a body of an
implant receiver by a first manufacturing method, the body
including an outer surface and spaced apart walls that define a
cavity configured for disposal of a spinal implant; forming at
least one layer onto at least a portion of the outer surface by a
second manufacturing method including an additive manufacturing
method wherein a processor instructs an additive manufacturing
apparatus to form the at least one layer.
In one embodiment, a bone screw is provided. The bone screw
comprises a shaft including at least one thread having an external
thread form. An implant receiver is formed by a first manufacturing
method. The receiver includes spaced apart walls defining a
U-shaped cavity configured for disposal of a spinal implant and an
outer surface. A layer is formed onto at least a portion of the
outer surface by a second manufacturing method.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more readily apparent from the
specific description accompanied by the following drawings, in
which:
FIG. 1 is a side view of components of one embodiment of a system
in accordance with the principles of the present disclosure;
FIG. 2 is a perspective view of components of one embodiment of a
system in accordance with the principles of the present
disclosure;
FIG. 3 is a perspective view of one embodiment of a system in
accordance with the principles of the present disclosure;
FIG. 4 is a cross section view of one embodiment of a system in
accordance with the principles of the present disclosure; and
FIG. 5 is a side view, in part cross section, of components of one
embodiment of a system in accordance with the principles of the
present disclosure.
DETAILED DESCRIPTION
The exemplary embodiments of a surgical system and related methods
of use disclosed are discussed in terms of medical devices for the
treatment of musculoskeletal disorders and more particularly, in
terms of a variable structured spinal implant. In some embodiments,
the spinal implant system includes a spinal implant comprising a
variable structured implant receiver.
In some embodiments, the spinal implant system of the present
disclosure comprises a spinal implant, such as, for example, an
implant receiver that is manufactured by combining traditional
manufacturing methods and additive manufacturing methods. In some
embodiments, a layer is applied by additive manufacturing in areas
where the implant receiver can benefit from materials, surface
texture, and/or other properties that can be associated with using
additive manufacturing.
In some embodiments, the implant receiver includes a hybrid
configuration that combines a manufacturing method, such as, for
example, one or more traditional manufacturing features and
materials and a manufacturing method, such as, for example, one or
more additive manufacturing features and materials. In some
embodiments, the spinal implant system of the present disclosure
comprises an implant receiver that promotes bony in-growth by
adding a layer thereto by additive manufacturing. In some
embodiments, the implant receiver includes a variable structure,
such as, for example, any combination of solid, roughened surfaces,
porous surfaces, honeycomb filled, structure having a trabecular
configuration, or other porous or roughened configurations. In some
embodiments, the implant receiver of the present disclosure aids in
the promotion of bony fusion. In some embodiments, the porous layer
is disposed about all or only a portion of a base, for example,
disposed about an outer diameter of the base. In some embodiments,
this configuration optimizes bony in-growth with the screw head of
a pedicle screw to promote fusion. In some embodiments, this
configuration resists and/or prevents toggle. In some embodiments,
the spinal implant system of the present disclosure comprises a
modular screw system including screw shaft assemblies and implant
receiver/head assemblies that may be joined together during
manufacturing or intra-operatively, such as, for example, during a
surgical procedure in an operating room.
In some embodiment, the implant receiver includes a porous or
surface textured layer at a bone interface portion of the implant
receiver. In some embodiments, the porous layer is configured to
enhance the implant-bone interface. In some embodiments, the porous
layer is applied by an additive manufacturing and other components
of the bone screw are manufactured by a traditional manufacturing
method. In some embodiments, the variable structure bone screw
provides for the mechanical strength of the bone screw and the
added porous layer enhances the implant-bone interface.
In some embodiments, additive manufacturing includes 3-D printing.
In some embodiments, additive manufacturing includes fused
deposition modeling, selective laser sintering, direct metal laser
sintering, selective laser melting, electron beam melting, layered
object manufacturing and stereolithography. In some embodiments,
additive manufacturing includes rapid prototyping, desktop
manufacturing, direct manufacturing, direct digital manufacturing,
digital fabrication, instant manufacturing and on-demand
manufacturing. In some embodiments, the spinal implant system
comprises one or more components, as described herein, of a spinal
implant being manufactured by a fully additive process and grown or
otherwise printed. In some embodiments, the implant receiver and/or
head assembly of the present disclosure includes a non-solid
portion, for example, a porous layer that is applied to a base of
the implant receiver and/or head assembly via additive
manufacturing, for example, 3-D printing. In some embodiments, this
configuration avoids compromising the integrity of a spinal
construct and promotes bone fusion.
In some embodiments, the spinal implants, surgical instruments
and/or medical devices of the present disclosure may be employed to
treat spinal disorders such as, for example, degenerative disc
disease, disc herniation, osteoporosis, spondylolisthesis,
stenosis, scoliosis and other curvature abnormalities, kyphosis,
tumor and fractures. In some embodiments, the spinal implants,
surgical instruments and/or medical devices of the present
disclosure may be employed with other osteal and bone related
applications, including those associated with diagnostics and
therapeutics. In some embodiments, the spinal implants, surgical
instruments and/or medical devices of the present disclosure may be
alternatively employed in a surgical treatment with a patient in a
prone or supine position, and/or employ various surgical approaches
to the spine, including anterior, posterior, posterior mid-line,
lateral, postero-lateral, and/or anterolateral approaches, and in
other body regions such as maxillofacial and extremities. The
spinal implants, surgical instruments and/or medical devices of the
present disclosure may also be alternatively employed with
procedures for treating the lumbar, cervical, thoracic, sacral and
pelvic regions of a spinal column. The spinal implants, surgical
instruments and/or medical devices of the present disclosure may
also be used on animals, bone models and other non-living
substrates, such as, for example, in training, testing and
demonstration.
The present disclosure may be understood more readily by reference
to the following detailed description of the embodiments taken in
connection with the accompanying drawing figures, which form a part
of this disclosure. It is to be understood that this application is
not limited to the specific devices, methods, conditions or
parameters described and/or shown herein, and that the terminology
used herein is for the purpose of describing particular embodiments
by way of example only and is not intended to be limiting. In some
embodiments, as used in the specification and including the
appended claims, the singular forms "a," "an," and "the" include
the plural, and reference to a particular numerical value includes
at least that particular value, unless the context clearly dictates
otherwise. Ranges may be expressed herein as from "about" or
"approximately" one particular value and/or to "about" or
"approximately" another particular value. When such a range is
expressed, another embodiment includes from the one particular
value and/or to the other particular value. Similarly, when values
are expressed as approximations, by use of the antecedent "about,"
it will be understood that the particular value forms another
embodiment. It is also understood that all spatial references, such
as, for example, horizontal, vertical, top, upper, lower, bottom,
left and right, are for illustrative purposes only and can be
varied within the scope of the disclosure. For example, the
references "upper" and "lower" are relative and used only in the
context to the other, and are not necessarily "superior" and
"inferior".
As used in the specification and including the appended claims,
"treating" or "treatment" of a disease or condition refers to
performing a procedure that may include administering one or more
drugs to a patient (human, normal or otherwise or other mammal),
employing implantable devices, and/or employing instruments that
treat the disease, such as, for example, microdiscectomy
instruments used to remove portions bulging or herniated discs
and/or bone spurs, in an effort to alleviate signs or symptoms of
the disease or condition. Alleviation can occur prior to signs or
symptoms of the disease or condition appearing, as well as after
their appearance. Thus, treating or treatment includes preventing
or prevention of disease or undesirable condition (e.g., preventing
the disease from occurring in a patient, who may be predisposed to
the disease but has not yet been diagnosed as having it). In
addition, treating or treatment does not require complete
alleviation of signs or symptoms, does not require a cure, and
specifically includes procedures that have only a marginal effect
on the patient. Treatment can include inhibiting the disease, e.g.,
arresting its development, or relieving the disease, e.g., causing
regression of the disease. For example, treatment can include
reducing acute or chronic inflammation; alleviating pain and
mitigating and inducing re-growth of new ligament, bone and other
tissues; as an adjunct in surgery; and/or any repair procedure.
Also, as used in the specification and including the appended
claims, the term "tissue" includes soft tissue, ligaments, tendons,
cartilage and/or bone unless specifically referred to
otherwise.
The following discussion includes a description of a spinal
implant, a method of manufacturing a spinal implant, related
components and methods of employing the surgical system in
accordance with the principles of the present disclosure. Alternate
embodiments are disclosed. Reference is made in detail to the
exemplary embodiments of the present disclosure, which are
illustrated in the accompanying figures. Turning to FIGS. 1-5,
there are illustrated components of a spinal implant system 10
including spinal implants, surgical instruments and medical
devices.
The components of spinal implant system 10 can be fabricated from
biologically acceptable materials suitable for medical
applications, including metals, synthetic polymers, ceramics and
bone material and/or their composites. For example, the components
of spinal implant system 10, individually or collectively, can be
fabricated from materials such as stainless steel alloys, aluminum,
commercially pure titanium, titanium alloys, Grade 5 titanium,
super-elastic titanium alloys, cobalt-chrome alloys, superelastic
metallic alloys (e.g., Nitinol, super elasto-plastic metals, such
as GUM METAL.RTM.), ceramics and composites thereof such as calcium
phosphate (e.g., SKELITE.TM.), thermoplastics such as
polyaryletherketone (PAEK) including polyetheretherketone (PEEK),
polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEK
composites, PEEK-BaSO.sub.4 polymeric rubbers, polyethylene
terephthalate (PET), fabric, silicone, polyurethane,
silicone-polyurethane copolymers, polymeric rubbers, polyolefin
rubbers, hydrogels, semi-rigid and rigid materials, elastomers,
rubbers, thermoplastic elastomers, thermoset elastomers,
elastomeric composites, rigid polymers including polyphenylene,
polyimide, polyimide, polyetherimide, polyethylene, epoxy, bone
material including autograft, allograft, xenograft or transgenic
cortical and/or corticocancellous bone, and tissue growth or
differentiation factors, partially resorbable materials, such as,
for example, composites of metals and calcium-based ceramics,
composites of PEEK and calcium based ceramics, composites of PEEK
with resorbable polymers, totally resorbable materials, such as,
for example, calcium based ceramics such as calcium phosphate,
tri-calcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium
sulfate, or other resorbable polymers such as polyaetide,
polyglycolide, polytyrosine carbonate, polycaroplaetohe and their
combinations.
Various components of spinal implant system 10 may have material
composites, including the above materials, to achieve various
desired characteristics such as strength, rigidity, elasticity,
compliance, biomechanical performance, durability and radiolucency
or imaging preference. The components of spinal implant system 10,
individually or collectively, may also be fabricated from a
heterogeneous material such as a combination of two or more of the
above-described materials. The components of spinal implant system
10 may be monolithically formed, integrally connected or include
fastening elements and/or instruments, as described herein.
Spinal implant system 10 includes a spinal implant comprising a
bone fastener, such as, for example, a bone screw 12. Bone screw 12
includes an implant receiver and/or head assembly having a variably
structured configuration that facilitates bone growth through bone
screw 12 and/or fixation of bone screw 12 with tissue. Bone screw
12 comprises a screw shaft 14 and an implant receiver 16. Receiver
16 includes a body 17 that defines an implant cavity 22 and a base
70. Base 70 includes a layer 80 applied by an additive
manufacturing process.
In various embodiments, body 17 has an even, uninterrupted edge
surface. Body 17 may also include an even, solid surface relative
layer 80, as described herein, which provides a variable
configuration bone screw 12.
In some embodiments, body 17 is fabricated by a first manufacturing
method. The manufacturing method can include a traditional
machining method, subtractive, deformative or transformative
manufacturing methods. In some embodiments, the traditional
manufacturing method may include cutting, grinding, rolling,
forming, molding, casting, forging, extruding, whirling, grinding
and/or cold working. In some embodiments, the traditional
manufacturing method includes components being formed by a medical
machining process. In some embodiments, medical machining processes
can include use of computer numerical control (CNC) high speed
milling machines, Swiss machining devices, CNC turning with living
tooling and/or wire EDM 4th axis. In some embodiments, the
manufacturing method includes a finishing process, such as, for
example, laser marking, tumble blasting, bead blasting, micro
blasting and/or powder blasting.
In some embodiments, body 17 includes a pair of spaced apart arms
18, 20. Arms 18, 20 define implant cavity 22 therebetween. Implant
cavity 22 is configured for disposal of a component of a spinal
construct, such as, for example, a spinal rod (not shown). In
various embodiments, arms 18, 20 each extend generally parallel to
an axis X1. In some embodiments, arm 18 and/or arm 20 may be
disposed at alternate orientations, relative to axis X1. For
example, arm 18 and/or arm 20 may be disposed transverse,
perpendicular and/or other angular orientations, such as acute or
obtuse, coaxial and/or may be offset or staggered relative to axis
X1. Arms 18, 20 each include an outer surface, which may be
arcuate, extending between a pair of side edges or surfaces.
In various embodiments, at least one of the outer surfaces and the
side surfaces of arms 18, 20 have at least one recess or cavity
therein configured to receive an insertion tool, compression
instrument, and/or instruments for inserting and tensioning bone
screw 12. In some embodiments, arms 18, 20 are connected at
proximal and distal ends thereof such that receiver 16 defines a
closed spinal rod slot.
Cavity 22 may be substantially U-shaped. In some embodiments, all
or only a portion of cavity 22 has alternate cross section
configurations, such as, for example, closed, V-shaped, W-shaped,
oval, oblong triangular, square, polygonal, irregular, uniform,
non-uniform, offset, staggered, and/or tapered.
Receiver 16 includes an inner surface 24. In various embodiments,
portion of surface 24 includes a thread form located adjacent arm
18 and adjacent arm 20. The thread form is configured for
engagement with a coupling member, such as, for example, a setscrew
(not shown), to retain the spinal rod within cavity 22. In some
embodiments, surface 24 may be disposed with the coupling member in
alternate fixation configurations, such as, for example, friction
fit, pressure fit, locking protrusion/recess, locking keyway and/or
adhesive. In some embodiments, all or only a portion of surface 24
may have alternate surface configurations to enhance engagement
with the spinal rod and/or the setscrew, such as, for example,
rough, arcuate, undulating, mesh, porous, semi-porous, dimpled
and/or textured. In some embodiments, receiver 16 may include
alternate configurations, such as, for example, closed, open and/or
side access.
In some embodiments, receiver 16 includes a surface configured for
disposal of a part, such as, for example, a crown (not shown). The
crown is configured for disposal within implant cavity 22. In some
embodiments, the crown includes a curved portion configured for
engagement with the spinal rod.
Base 70 includes porous layer 80 to enhance fixation and/or
facilitate bone growth, as described herein. Layer 80 is applied
with a second manufacturing, as described herein. In some
embodiments, the manufacturing method can include an additive
manufacturing method by disposing a material onto a surface 78 of a
wall 72, as described herein. All or a portion of base 70 is
configured to interface bone. Layer 80 is provided to increase a
base 70-to-bone interface.
Base 70 having layer 80 enhances fixation and/or facilitates bone
growth, as described herein. In some embodiments, tissue becomes
imbedded with layer 80 to promote bone growth, enhance fusion of
bone screw 12 with vertebral tissue, and/or prevent toggle of bone
screw 12 in one or multiple motion planes.
Body 17 is in various embodiments manufactured by a traditional
manufacturing process (not including additive manufacturing, for
instance), and layer 80 is applied to surface 78 by an additive
manufacturing process. Having body 17 and the other components of
bone screw 12 manufactured by traditional manufacturing processes
maintains the mechanical performance characteristics of bone screw
12, while also enhancing bone growth and fusion.
Base 70 of receiver 16 includes wall 72. Wall 72 includes an inner
surface 74 that defines a cavity 76, and outer surface 78. Cavity
76 is configured for disposal of a head 182 of screw shaft 14. In
various embodiments, wall 72 includes an even, uninterrupted
configuration and includes an even, solid surface 78 relative to
the surface of layer 80. Surface 78 is configured for providing a
fabrication platform for forming layer 80 thereon using a second
manufacturing method such as, for example, an additive
manufacturing method, as described herein. In some embodiments, an
overall width of wall 72 including layer 80 (e.g., outside
diameter, or maximum width) is the same as a width of a traditional
receiver. In some embodiments, receiver 16 has a solid
configuration relative to the layer 80. In some embodiments,
receiver 16 is connectable with a bone screw shaft.
Layer 80 is applied to at least a portion of an outer circumference
of surface 78. In some embodiments, layer 80 includes a portion 82
and a portion 84, as shown in FIGS. 2 and 3. Portion 82 includes a
first thickness t1 and portion 84 includes a second thickness t2,
as shown in FIG. 2. In some embodiments, portion 82 includes a
tapered portion 86 that connects portion 82 and portion 84. In some
embodiments, layer 80 has various configurations along surface 78,
such as, a non-solid configuration, such as, for example, a porous
structure and/or a trabecular configuration.
In some embodiments, additive manufacturing includes 3-D printing,
as described herein. In some embodiments, additive manufacturing
includes fused deposition modeling, selective laser sintering,
direct metal laser sintering, selective laser melting, electron
beam melting, layered object manufacturing and stereolithography.
In some embodiments, additive manufacturing includes rapid
prototyping, desktop manufacturing, direct manufacturing, direct
digital manufacturing, digital fabrication, instant manufacturing
or on-demand manufacturing.
In some embodiments, layer 80 is applied by additive manufacturing,
as described herein, and mechanically attached to surface 78 by,
for example, welding, threading, adhesives and/or staking. In some
embodiments, layer 80 has a porous configuration, a lattice, a
trabecular configuration and/or a roughened surface to promote bone
growth through the layer. In some embodiments, additive
manufacturing includes heating a material in a selective material
formation onto a portion of the outer surface of the implant
receiver.
In various embodiments, the non-solid configuration provides one or
a plurality of pathways to facilitate bone through growth within,
and in some embodiments all of the way through, from one surface to
an opposite surface of bone screw 12. In some embodiments, one or
more portions, layers and/or substrates of layer 80 may be disposed
side by side, offset, staggered, stepped, tapered, end to end,
spaced apart, in series and/or in parallel. In some embodiments,
layer 80 is disposed about an entire outer circumference of
receiver 16. In some embodiments, layer 80 disposed about an outer
circumference of a lower portion near base 70 of receiver 16, as
shown in FIGS. 2 and 3.
In some embodiments, layer 80 defines a thickness, which may be
uniform, undulating, tapered, increasing, decreasing, variable,
offset, stepped, arcuate, angled and/or staggered. In some
embodiments, layer 80 includes one or more layers of a matrix of
material. In some embodiments, layer 80 includes one or a plurality
of cavities, spaces and/or openings. In some embodiments, layer 80
forms a rasp-like configuration. In some embodiments, layer 80 is
configured to engage tissue, such as, for example, cortical bone
and/or cancellous bone, such as, to cut, shave, shear, incise
and/or disrupt such tissue. In some embodiments, all or a portion
of layer 80 may have various configurations, such as, for example,
cylindrical, round, oval, oblong, triangular, polygonal having
planar or arcuate side portions, irregular, uniform, non-uniform,
consistent, variable, horseshoe shape, U-shape or kidney bean
shape. Layer 80 may be rough, textured, porous, semi-porous,
dimpled, knurled, toothed, grooved and/or polished to facilitate
engagement and cutting of tissue.
In some embodiments, the non-solid configuration is configured as a
lattice extending along surface 78. In some embodiments, the
lattice may include one or more portions, layers and/or substrates.
Disclosures herein involving a porous, or other particular type of
non-solid structure, are meant to disclose at the same time
analogous embodiments in which other non-solid structure in
addition or instead of the particular type of structure.
In some embodiments, layer 80 is fabricated according to
instructions received from a computer and processor based on the
digital rendering and/or data of the selected configuration, via
the additive manufacturing process. See also, the examples and
disclosure of the additive and three-dimensional manufacturing
systems and methods shown and described in commonly owned and
assigned U.S. patent application Ser. No. 15/889,355, filed Feb. 6,
2018; and the examples and disclosure of the additive and three
dimensional manufacturing systems and methods shown and described
in commonly owned and assigned U.S. patent application Ser. Nos.
15/666,305 and 15/666,281, filed Aug. 1, 2018; the entire contents
of each of these references being hereby incorporated by reference
herein in their respective entireties.
In one embodiment, one or more manufacturing methods for
fabricating layer 80 and other components of bone screw 12, such
as, for example, screw shaft 14 and receiver 16 include imaging
patient anatomy with imaging techniques, such as, for example,
x-ray, fluoroscopy, computed tomography (CT), magnetic resonance
imaging (MRI), surgical navigation, bone density (DEXA) and/or
acquirable 2-D or 3-D images of patient anatomy. Selected
configuration parameters of screw shaft 14, receiver 16 and layer
80 and/or other components of bone screw 12 are collected,
calculated and/or determined. Such configuration parameters can
include one or more of patient anatomy imaging, surgical treatment,
historical patient data, statistical data, treatment algorithms,
implant material, implant dimensions, porosity and/or manufacturing
method. In some embodiments, the configuration parameters can
include implant material and porosity of layer 80 determined based
on patient anatomy and the surgical treatment. In some embodiments,
the implant material includes a selected porosity of layer 80, as
described herein.
In some embodiments, the processor can instruct motors (not shown)
that control movement and rotation of components, for example, a
build plate 200, receiver 16 and/or laser emitting devices, as
described herein. In some embodiments, layer 80 is applied by
utilizing a radiation source to melt and solidify a material M onto
surface 78 into a desired three-dimensional shape based on the
selected configuration parameters, as described herein. In some
embodiments, the radiation source includes a laser device 224, as
shown in FIG. 5, which comprises a carbon dioxide laser. In some
embodiments, laser device 224 may include a beam of any wavelength
of visible light or UV light. In some embodiments, alternative
forms of radiation, such as, for example, microwave, ultrasound or
radio frequency radiation are provided. In some embodiments, laser
device 224 is configured to be focused on a portion of surface 78
to sinter material M deposited thereon, as shown in FIG. 5. In some
embodiments, laser device 224 emits a beam having a diameter
between about 0.01 mm and about 0.8 mm. In some embodiments, the
diameter of the beam may be between about 0.1 mm and about 0.4 mm.
In some embodiments, the diameter of the beam is adjustable to
customize the intensity of the sintering.
Build plate 200 includes a surface that defines one or a plurality
of openings 204. Each opening 204 is configured for disposal of
receiver 16 to orient base 70 as a fabrication platform for forming
layer 80 thereon with an additive manufacturing method, as
described herein. Surface 78 extends from opening 204 to orient
surface 78 for selective laser melting with a powder bed process by
the radiation source.
Build plate 200 is mounted with a platform 226 such that build
plate 200 can be moved relative to an enclosure in one or more
directions to generate layer 80 on surface 78, layer by layer,
based on the digital rendering and/or data. In some embodiments,
build plate 200 can be translated vertically, horizontally or
diagonally, rotated, pivoted, raised and/or lowered to generate the
distal portion. In some embodiments, build plate 200 can be moved
relative to the enclosure slidably, continuously, incrementally,
intermittently, automatically, manually, selectively and/or via
computer/processor control. In some embodiments, an apparatus
comprising an additive manufacturing device that employs selective
laser melting with a powder bed process to create 3D objects is
provided. See, for example, the Lasertec 30 SLM additive
manufacturing machine manufactured by DMG MORI Co. Ltd. located at
2-35-16 Meieki, Nakamura-ku, Nagoya City 450-0002, Japan.
In some embodiments, the selected configuration parameters of layer
80 and/or other components of bone screw 12 are patient specific.
In some embodiments, the selected configuration parameters of layer
80 and/or other components of bone screw 12 are based on generic or
standard configurations and/or sizes and not patient specific. In
some embodiments, the selected configuration parameters of layer 80
and/or other components of bone screw 12 are based on one or more
configurations and/or sizes of components of a kit of spinal
implant system 10 and not patient specific.
Screw shaft 14 defines an even, uninterrupted edge surface and
includes an even, solid surface relative to the surface of layer
80. Shaft 180 is configured to penetrate tissue, such as, for
example, bone. In some embodiments, shaft 180 includes an outer
surface having an external thread form. In some embodiments, the
external thread form may include a single thread turn or a
plurality of discrete threads. Head 182 includes a tool engaging
portion configured to engage a surgical tool or instrument, as
described herein. In some embodiments, the tool engaging portion
includes a hexagonal cross-section to facilitate engagement with a
surgical tool or instrument, as described herein. In some
embodiments, the tool engaging portion may have alternative
cross-sections, such as, for example, rectangular, polygonal,
hexalobe, oval, or irregular. In some embodiments, head 182
includes a plurality of ridges to improve purchase of head 182 with
the crown. Head 182 is configured for attachment with receiver 16,
as described herein.
In some embodiments, the external thread form is fabricated to
include a fine, closely-spaced and/or shallow configuration to
facilitate and/or enhance engagement with tissue. In some
embodiments, the external thread form is fabricated to be
continuous along shaft 180. In some embodiments, the external
thread form is fabricated to be intermittent, staggered,
discontinuous and/or may include a single thread turn or a
plurality of discrete threads. In some embodiments, shaft 180 is
fabricated to include penetrating elements, such as, for example, a
nail configuration, barbs, expanding elements, raised elements,
ribs, and/or spikes. In some embodiments, the external thread form
is fabricated to be self-tapping or intermittent at a distal tip.
In some embodiments, the distal tip may be rounded. In some
embodiments, the distal tip may be self-drilling. In some
embodiments, the distal tip includes a solid outer surface.
Surface 74 facilitates engagement of head 182 with base 70 via a
pressure and/or force fit connection. In some embodiments, surface
74 facilitates a non-instrumented assembly with receiver 16 and
head 182 via an expandable ring. In some embodiments, receiver 16
may be disposed with head 182 in alternate fixation configurations,
such as, for example, friction fit, pressure fit, locking
protrusion/recess, locking keyway and/or adhesive. In some
embodiments, receiver 16 is configured for rotation relative to
head 182. In some embodiments, receiver 16 is configured for
rotation in range of 360 degrees relative to head 182 to facilitate
positioning of shaft 180 with tissue. In some embodiments, receiver
16 is configured for selective rotation in range of 360 degrees
relative to and about head 182 such that shaft 180 is selectively
aligned for rotation in a plane relative to receiver 16.
In some embodiments, receiver 16 is manually engageable with screw
shaft 14 in a non-instrumented assembly, as described herein. In
some embodiments, manual engagement and/or non-instrumented
assembly of receiver 16 and screw shaft 14 includes coupling
without use of separate and/or independent instrumentation engaged
with screw shaft 14 components to effect assembly. In some
embodiments, manual engagement and/or non-instrumented assembly
includes a practitioner, surgeon and/or medical staff grasping
receiver 16 and screw shaft 14 and forcibly assembling the
components. In some embodiments, manual engagement and/or
non-instrumented assembly includes a practitioner, surgeon and/or
medical staff grasping receiver 16 and screw shaft 14 and forcibly
snap fitting the components together, as described herein. In some
embodiments, manual engagement and/or non-instrumented assembly
includes a practitioner, surgeon and/or medical staff grasping
receiver 16 and screw shaft 14 and forcibly pop fitting the
components together and/or pop fitting receiver 16 onto screw shaft
14, as described herein. In some embodiments, a force in a range of
about 2 to about 50 N is required to manually engage receiver 16
and screw shaft 14 and forcibly assemble the components. For
example, a force in a range of about 2 to about 50 N is required to
snap fit and/or pop fit assemble receiver 16 and screw shaft 14. In
some embodiments, a force in a range of about 5 to about 10 N is
required to manually engage receiver 16 and screw shaft 14 and
forcibly assemble the components. For example, a force in a range
of about 5 to about 10 N is required to snap fit and/or pop fit
assemble receiver 16 and screw shaft 14. In some embodiments, screw
shaft 14 is manually engaged with base 70 and/or receiver 16 in a
non-instrumented assembly, as described herein, such that removal
of receiver 16 and screw shaft 14 requires a force and/or a
pull-out strength of at least about 5000 N. In some embodiments,
this configuration provides manually engageable components that are
assembled without instrumentation, and subsequent to assembly, the
assembled components have a selected pull-out strength and/or can
be pulled apart, removed and/or separated with a minimum required
force. In some embodiments, spinal implant system 10 comprises a
spinal implant kit, as described herein, which includes a plurality
of screw shafts 14 and/or receivers 16.
In some embodiments, bone screw 12 can include various
configurations, such as, for example, a posted screw, a pedicle
screw, a bolt, a bone screw for a lateral plate, an interbody
screw, a uni-axial screw, a fixed angle screw, a multi-axial screw,
a side loading screw, a sagittal adjusting screw, a transverse
sagittal adjusting screw, an awl tip, a dual rod multi-axial screw,
midline lumbar fusion screw and/or a sacral bone screw.
In assembly, operation and use, spinal implant system 10 is
employed to treat an affected section of vertebrae. A medical
practitioner obtains access to a surgical site including the
vertebrae in any appropriate manner, such as through incision and
retraction of tissues. The components of spinal implant system 10
including bone screw 12 are employed to augment a surgical
treatment. Bone screw 12 can be delivered to a surgical site as a
pre-assembled device. In some embodiments, bone screw 12 can be
delivered to a surgical site assembled in situ. Spinal implant
system 10 may be completely or partially revised, removed or
replaced.
Surgical system 10 may be used with surgical methods or techniques
including open surgery, mini-open surgery, minimally invasive
surgery and percutaneous surgical implantation, whereby the
vertebrae is accessed through a mini-incision, or sleeve that
provides a protected passageway to the area. Once access to the
surgical site is obtained, a surgical treatment, for example,
corpectomy and/or discectomy, can be performed for treating a spine
disorder.
Bone screw 12 is connected with a surgical instrument, such as, for
example, a driver (not shown) and is delivered to the surgical
site. Bone screw 12 is manipulated including rotation and/or
translation for engagement with cortical bone and/or cancellous
bone. Receiver 16 is manually engaged with screw shaft 14 in a
non-instrumented assembly, as described herein. Bone screw 12
including base 70 having layer 80 enhances fixation and/or
facilitates bone growth, as described herein. In some embodiments,
tissue becomes imbedded with layer 80 to promote bone growth,
enhance fusion of bone screw 12 with vertebral tissue, and/or
prevent toggle of bone screw 12 components. In some embodiments,
the layer is disposed about at least a portion of an outer
circumference of the base.
It will be understood that various modifications may be made to the
embodiments disclosed herein. Therefore, the above description
should not be construed as limiting, but merely as exemplification
of the various embodiments. Those skilled in the art will envision
other modifications within the scope and spirit of the claims
appended hereto.
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